Background

MS436 is a potent and selective small-molecule inhibitor of BRD4 with Ki values of ＜0.085μM and 0.34μM, respectively for BrD1 and BrD2 [1].

BRD4 plays a role in gene transcription and is a drug target for cancer and inflammation. It has two bromodomains. MS436 is a diazobenzene compound, it is designed from the SAR studies to have higher selectivity. In vitro fluorescent anisotropy assay shows MS436 has about 10-fold higher affinity of BrD1 over BrD2. MS436 binds to BRD4 through a set of water-mediated interaction and this is the molecular basis for the binding affinity. MS436 also has activity to CBP BrD. In RAW264.7 cells, MS436 can block NF-κB-directed NO production and block the expression of proinflammatory cytokine interleukin (IL)-6 induced by LPS [1].